Carbon dioxide gas has been cited as one factor in global warming, and emissions of carbon dioxide gas have increased in conjunction with economic growth. Accordingly, there is a serious need for reducing the atmospheric concentration of carbon dioxide gas on a global scale.
Conventionally, as carbon dioxide gas fixation methods, there has been proposal of a method in which carbon dioxide gas is absorbed by an alkaline solution such as amine, and is separated and recovered by heating; or a method in which carbon dioxide gas that has been separated and recovered using a porous gas permeation membrane is liquefied, and stored in the deep ocean or underground. However, the foregoing methods not only impose environmental burdens, but also involve possibility of re-release of the carbon dioxide gas stored in the ocean or underground.
As another carbon dioxide gas fixation method, there is a method shown in Patent Document 1.